High critical current density YBa2Cu3O7−δ tapes prepared by the surface-oxidation epitaxy method

Epitaxial deposition of NiO film on a cube-textured Ni substrate by metal-organic chemical vapor deposition

“…Similar enhancement in the texture of the buffer layer was also reported for the films prepared by electron-beam evaporation, sputtering and PLD [10|. Matsumoto et al [4] formed a biaxially textured NiO buffer using the SOE method on a cube-texture Ni substrate. The in-plane texture of the NiO film prepared by the SOE method shows a relatively large deviation of 10-14 ~ which is ]arger than that of the starting Ni substrate.…”

“…Therefore, attempting to deposit an NiO film having a cube texture on an Ni substrate seems paradoxical since the oxidation of an Ni substrate during the deposition of NiO film induces the development of (111) oriented NiO film, which should be avoided in order to obtain an NiO film having a cube texture. However, Matsumoto et aL obtained a cube textured NiO by oxidizing a cube textured Ni substrate in flowing oxygen [8] or an Ar atmosphere [4]. Therefore, it is still unclear whether the oxidation of an Ni substrate always leads to the development of a (111) orientation of a buffer film.…”

“…Ginsbach et al [3] showed that the NiO can be used as a buffer layer for YBCO fill by depositing YBCO films on oxidized textured NiO sheets and on (100) and (110) oriented NiO single crystals. Recently, Matsumoto et al [4] also successfully fabricated a Ni/NiO/MgO/YBCO struc~ne by a surface oxidation epitaxy (SOE) method and the Jc was measure at as high as 50 kA/cm 2. From the results of Ginzbach et al and Matsutomo et al, it is thought that NiO is also one of the potential materials to be used as a buffer layer of a YBCO coated conductor.…”

Growth model and the effect of CuO nanocrystallites on the properties of chemically derived epitaxial thin films of YBa2Cu3O7−x

“…YBCO films are mainly fabricated by physical vapor deposition routes, such as pulsed laser ablation or sputtering. 5,6 Although they can produce fairly good YBCO films relatively easily, these processes have some drawbacks in terms of cost performance for mass production: they require expensive vacuum chambers, and the reproducibility of the critical current density ͑J c ͒ of the YBCO films is not good enough because of the essential difficulty of controlling the composition. On the other hand, as a chemical route, metalorganic deposition has been studied for a long time, because it does not require a vacuum system and enables low-cost mass production of YBCO films.…”

Research of surface-oxidation epitaxy of NiO films on cube textured Ni tapes

“…The drawbacks of this approach are that the Ce02 is subject to cracking, which degrades the effect of the buffer layer, and that the both of CeOz and,YSZ have to be deposited using PLD, same as the YBCO, which makes the process sequential and lengthy. It has been reported that the critical current density of an YBCO composite tape) produced by pulsed laser deposition (PLD) of YBCO film on a cube-textured NiO,j previously fabricated by SOB of a cube-textured Ni, was between 4 xl04 Acm-2 and 6 xl0 4 i Acm· 2 (at 17K, and OT) [6]. This value is approximately two orders of magnitude lower'; than the critical current density of an YBCO/Ce02INi tape where the Ce02 buffer layer is) produced by PLD using ion beam assisted deposition (lEAD) on randomly-oriented Ni, by PLD on RABiTS Ni [1,7].…”